University of Arkansas researchers study 2 deadly tornadoes

Tornado damage in Joplin on Monday, May 23, 2011.

FAYETTEVILLE, Ark. (AP) - New research from the University of Arkansas finds that tornadoes cause greater damage when traveling uphill - and that the twisters tend to climb toward higher elevations rather than going downhill.

Engineering researchers studied images of the 2011 deadly tornadoes in Tuscaloosa, Ala., and Joplin, Mo. The research team found similarities between the two tornadoes and say the findings likely apply to all tornadoes.

Researchers also found that when a region is surrounded by hills, tornadoes skip or hop over the valleys below. Damage is noticed only on the top of the hills.